Spectroscopic investigations of hydrogen bond dynamics in liquid water

Many of the remarkable physical and chemical properties of liquid water are due to the strong influence hydrogen bonds have on its microscopic dynamics. However, because of the fast timescales involved, there are relatively few experimental techniques capable of directly probing rearrangements of water's hydrogen bonded network. In this thesis, I investigate ultrafast intermolecular dynamics of water with time-resolved Raman and time-resolved infrared spectroscopies. These two sets of measurements provide a complimentary view of the collective and local behavior of molecular motions. Using a novel Raman technique, spatially masked optical Kerr effect spectroscopy, I first measured interaction-induced fluctuations in the isotropic many-body polarizability of water and several other liquids. In contrast to the behavior of simple liquids, the isotropic response of water is exceedingly fast and distinct from the well-known anisotropic response. I then designed and built an optical parametric amplifier that produces sub-50 fs pulses of mid-IR light to investigate the intermolecular dynamics of water through their effect on the OH oscillator of HOD in D20. By analyzing the results of three-pulse vibrational echo and polarization- selective pump-probe measurements with a comprehensive theory to describe vibrational dynamics, I extracted the timescales for vibrational relaxation, dephasing and molecular reorientations.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Chemistry.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2004

Author dc:creator

• Fecko, Christopher J., 1975-

Advisor dc:contributor.advisor

• Andrei Tokmakoff.

• Chemistry.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/16652

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/16652